KR102428830B1 - Air-supplier and controlling method for the air-supplier - Google Patents

Abstract

The present invention relates to an air compressor and a method for controlling the same. An object of the present invention is to improve the durability and driving quality of the airfoil bearing in the air compressor by injecting air into the airfoil bearing provided around or at the end of the rotating shaft in the air compressor at the initial stage of operation of the air compressor, and an air compressor and the same To provide a control method.

Description

Air compressor and controlling method thereof

The present invention relates to an air compressor and a control method thereof, and more particularly, to an air compressor capable of improving durability and driving quality of an airfoil bearing in an air compressor and a control method thereof.

Traditionally, automobiles have used an engine driven by burning fossil fuel as a power source. However, due to environmental pollution problems and fossil fuel depletion, recently, a hybrid vehicle that uses an electric motor and an engine together or an electric vehicle using only a motor Research on the same eco-friendly vehicle is actively and rapidly progressing. As a type of battery used in such an eco-friendly vehicle, a fuel cell in which hydrogen and oxygen are supplied to generate electric energy through an electrochemical reaction, which is a reverse reaction of electrolysis of water, is currently widely used, and related research is being actively conducted.

In supplying oxygen to the fuel cell stack, a method of supplying air containing oxygen by compression is generally used. In general, fuel cell vehicles are equipped with a fuel cell stack of 80kW class, and when operated under a pressurized condition, the supplied air has a high pressure of 1.2 to 3.0 bar. In order to supply high-pressure air at this level, it is necessary for the air compressor to rotate at a rotational speed of about 5,000 to 10,000 rpm. Korean Patent Registration No. 0962903 (“Integrated Hydrogen Recirculation Blower for Fuel Cell Vehicles”, June 1, 2010), etc. discloses various technical contents regarding an air compressor that supplies compressed air to such a fuel cell stack.

An air compressor is a device for sucking in, compressing, and discharging air using an impeller connected to a rotating shaft, and a rotating shaft rotating the impeller is provided with a bearing to reduce friction with the housing during rotation. Since the impeller used in the air compressor rotates at a fairly high speed, in general, the impeller rotating shaft has a journal bearing provided in a form surrounding the outer circumferential surface of the rotating shaft, and a collapse provided at a position where a load is applied in the rotational shaft extension direction. Both types of thrust bearings are available.

On the other hand, traditionally, various mechanical devices have widely used ball bearings in which a plurality of steel balls are included between frames, and these ball bearings may also be used for bearings provided on the impeller rotating shaft. In recent years, the use of airfoil bearings, which is much more effective in reducing friction than ball bearings, is also increasing. Ball bearings are also applied to bearings provided on the impeller rotating shaft, but recently, airfoil bearings are increasingly applied.

1 schematically shows the structure of a general airfoil journal bearing. As shown in FIG. 1(A), the airfoil journal bearing has a cylindrical housing 1 surrounding the rotation shaft 10, and is disposed to be inscribed on the inner circumferential surface of the housing 1 and has a shape capable of having an elastic force. and a bump foil 2 and a top foil 3 disposed to surround the rotation shaft 10 so that the elastic force of the bump foil 2 can be uniformly transmitted to the rotation shaft 10 . When the rotating shaft 10 rotates at a high speed, dynamic pressure is formed in the space between the foils 2 and 3 and the rotating shaft 10 by air flow, and accordingly, the foils 2 and 3 and the Since an air-gap is formed between the rotation shafts 10 , the rotation shaft 10 can be rotated without friction with the foils 2 and 3 . Although the airfoil journal bearing is illustrated in FIG. 1 , the thrust airfoil bearing also differs in the shape of the housing 1 and the positions at which the foils 2 and 3 are disposed, but the basic configuration is similar to this.

Figure 2 shows a conventional air compressor structure and bearing position. As shown in Fig. 2, the rotary shaft 131 of the conventional air compressor 100' is provided with a plurality of ball bearings 151' and 152' to reduce friction in many cases. However, as described above, in the case of an air compressor for supplying high-pressure air to the fuel cell stack, it rotates at a higher rotational speed than that required by other existing devices. In the case of a ball bearing, friction can be greatly reduced, but since the friction force is not 0, when the rotating shaft rotates at such a high speed, friction occurs in the ball bearing, and the temperature rises rapidly and there is a very high risk of damage.

The airfoil bearing has the best performance in terms of friction reduction effect because the friction force can ideally be almost zero. However, it has a weakness in that it has relatively insufficient rigidity compared to ball bearings and the like due to the structural characteristic of including very thin foils. In addition, since sufficient dynamic pressure is not generated in a stationary state or in the initial stage of operation, an air gap between the foil-rotation shaft is not sufficiently formed, so that the rotation shaft 10 is lowered by gravity as shown in FIG. (2) There is a problem that the friction reduction performance is considerably lowered because it is in contact with (3).

1. Korean Patent Registration No. 0962903 (“Integrated Hydrogen Circulation Blower for Fuel Cell Vehicles”, 2010.06.01)

Accordingly, the present invention has been devised to solve the problems of the prior art as described above, and an object of the present invention is to inject air into the airfoil bearing provided around or at the end of the rotating shaft in the air compressor at the beginning of the operation of the air compressor. An object of the present invention is to provide an air compressor for an air compressor capable of improving the durability and driving quality of the airfoil bearing in the air compressor, and a method for controlling the same.

The air compressor 100 of the present invention for achieving the above object sucks, compresses and discharges gas using an impeller 110 rotating by a rotating shaft 131, and the rotating shaft 131 is located around the At least one airfoil bearing formed in the form of a journal bearing or a thrust bearing is provided, and an air supply unit that receives and stores a portion of the compressed air discharged from the air compressor 100 and supplies air to the inside of the airfoil bearing (500) may be included.

More specifically, the air compressor 100 includes a core 111 and a plurality of blades 112, and the impeller 110 rotates by the rotation shaft 131 to suck and compress gas and discharge it; It includes an impeller chamber front member 121 and an impeller chamber rear member 122 including a gas inlet 121a, a gas outlet 121b, and a gas flow path 121c, and receiving and supporting the impeller 110 impeller chamber 120; a front bearing 151 supported by the impeller chamber rear member 122 to support the front end side of the rotation shaft 131 and formed in the form of an airfoil journal bearing; An air storage unit 510 for storing compressed air, one end connected to the air storage unit 510 and the other end of the gas discharge port 121b and the other end to receive and store a portion of the compressed air discharged through the gas discharge port 121b A storage flow path 520 connected, one end connected to the air storage unit 510 and a supply flow path 530 having the other end connected to the front bearing 151 to supply air to the inside of the front bearing 151, the air supply unit 500 including a control unit 550 for controlling the opening and closing of the storage passage 520 or the supply passage 530 ; may include.

At this time, in the air compressor 100, as the impeller 110 rotates, gas is sucked through the gas inlet 121a formed coaxially with the core 111, and the sucked gas is applied to the blade. It is compressed while flowing into the gas flow path 121c along the 112, and the compressed gas is collected at the gas outlet 121b and discharged to the outside.

In addition, the air supply unit 500 includes a storage passage valve 525 provided on the storage passage 520 , and a supply passage valve provided on the supply passage 530 and controlled to be opened and closed by the controller 550 . (535) may be further included. At this time, the air supply unit 500 is formed in the form of a check valve in which the storage passage valve 525 is opened when the pressure in the gas discharge port 121b is greater than the pressure in the air storage unit 510 and closed otherwise. Alternatively, the storage passage valve 525 may be formed such that opening and closing is controlled by the control unit 550 .

Also, the air supply unit 500 may further include an integrated flow path 540 that integrates the storage flow path 520 and the supply flow path 530 and connects to the air storage unit 510 . In this case, the air supply unit 500 may further include an integrated flow path valve 545 provided on the integrated flow path 540 and formed in the form of a three-way valve whose opening and closing is controlled by the control unit 550 .

In addition, the air compressor 100 includes a motor 130 connected to the rear end of the impeller 110 through the rotation shaft 131 to rotate the impeller 110 ; a motor room 140 including a front member of the motor room 141 and a rear member of the motor room 142 , connected to the rear end of the impeller room 120 and accommodating and supporting the motor 130 ; Further comprising, the rear bearing 152 being supported by the motor chamber rear member 142 or the turbine chamber member to support the rear end side of the rotating shaft 131, and formed in the form of an airfoil journal bearing; may further include.

At this time, the air supply unit 500 has an additional supply passage ( 530a) may be further included. In this case, the air supply unit 500 may further include an additional supply passage valve 535a provided on the additional supply passage 530a and opened and closed by the controller 550 .

In addition, the air compressor 100, a flange (131a) protruding from the rear end of the rotary shaft 131, and inserted into the groove formed in the motor chamber rear member 142 or the turbine chamber member; an end bearing 153 provided between the flange 131a and the groove and formed in the form of an airfoil thrust bearing; may further include.

At this time, the air supply unit 500 has one end connected to the air storage unit 510 and the other end is an additional supply passage connected to the end bearing 153 so as to supply air to the inside of the end bearing 153 ( 530b) may be further included. In this case, the air supply unit 500 may further include an additional supply passage valve 535b provided on the additional supply passage 530b and opened and closed by the controller 550 .

In addition, in the method of controlling the air compressor 100 of the present invention, the gas is sucked in, compressed and discharged using the impeller 110 rotated by the rotating shaft 131 , and journal bearings or thrust bearings are located around the rotating shaft 131 . At least one airfoil bearing formed in a shape is provided, and an air supply unit 500 that receives and stores a portion of the compressed air discharged from the air compressor 100 and supplies air to the inside of the airfoil bearing comprises an air supply unit 500 In the air compressor (100) control method for controlling the air compressor (100), the starting standby step of waiting in a state in which the rotating shaft (131) is stopped; an air supply step in which air is supplied to the inside of the airfoil bearing by the air supply unit 500; a starting step of starting the air compressor 100 by rotating the rotary shaft 131 when an air gap is formed between the rotary shaft 131 and the airfoil bearing by the air supply step; an air storage step in which a part of compressed air suctioned and compressed by the operation of the air compressor 100 and discharged is stored in the air supply unit 500; a supply stopping step in which the air supply to the inside of the airfoil bearing is stopped by the air supply unit 500; may include.

At this time, in the air compressor 100 control method, in the air storage step, if the pressure in the space from which the gas is discharged from the air compressor 100 is greater than the pressure in the air storage space of the air supply unit 500, it is opened. Otherwise, whether to store air is controlled by a check valve that is closed, or whether to store air is controlled by an automatic control valve whose opening and closing is controlled by the control unit 550 in the air storage step. At this time, in the air compressor 100 control method, in the air storage step, when the rotation speed of the rotary shaft 131 reaches a predetermined standard by the controller 550, air storage is started, or the rotary shaft After a predetermined time passes after the rotation of the 131 is started, the air storage may be started.

Also, in the air compressor 100 control method, in the air supply step, whether air is supplied or not may be controlled by an automatic control valve whose opening and closing is controlled by the controller 550 .

Also, in the air compressor 100 control method, in the supply interruption step, when the rotation speed of the rotation shaft 131 reaches a predetermined criterion by the control unit 550, the air supply is stopped, or the rotation shaft ( 131) may be made such that the air supply is stopped after a predetermined time has elapsed after the rotation is started.

In the conventional air compressor, sufficient dynamic pressure is not generated at the initial stage of operation of the air compressor, so an air gap between the foil and the rotating shaft is not sufficiently formed, and there is a problem in that the contact between the foil and the rotating shaft occurs. However, according to the present invention, there is a great effect of maximizing friction reduction performance by resolving this problem by injecting air into the airfoil bearing provided around or at the end of the rotating shaft in the air compressor at the initial stage of operation of the air compressor. In particular, in the case of the prior art, there was a problem that the foil was damaged by the rotation of the rotating shaft in a state in which the foil-rotating shaft was in contact with each other because a sufficient air gap was not secured at the initial stage of operation. Since the rotation of the rotation shaft is performed in a state in which the air gap between the foil and the rotation shaft is sufficiently secured, the risk of damage to the foil can be drastically reduced.

As such, according to the present invention, by reducing the risk of damage to the airfoil bearing provided around the rotation shaft of the impeller performing air compression in the air compressor and improving the durability, the effect of improving the durability of the air compressor itself as a result is have. In addition, as described above, there is an effect of improving the driving quality of the air compressor by solving the problems at the initial stage of operation. In addition, the conventional airfoil bearings provided around the rotating shaft, which have superior friction reduction performance than conventional ball bearings, are freed from the limitations of actively adopting airfoil bearings on the rotating shaft of the air compressor due to their relatively lack of rigidity and durability. By allowing replacement to be applied to bearings, there is also the effect of improving the driving performance of the air compressor.

1 is a general airfoil journal bearing structure.
Figure 2 is a conventional air compressor structure and bearing position.
3 is a first embodiment of the air compressor of the present invention.
4 is an air flow in the air compressor of the present invention.
5 is an embodiment of a bearing air supply structure;
6 is an embodiment of an airfoil journal bearing according to a bearing air supply structure;
7 is a second embodiment of the air compressor of the present invention.
8 is a flowchart of an air compressor control method of the present invention.

Hereinafter, an air compressor and a control method thereof according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

Basic configuration of the air compressor of the present invention

3 shows a first embodiment of the air compressor of the present invention. The air compressor 100 of the present invention has a configuration in which conventionally, ball bearing-type bearings are provided on the rotating shaft of the air compressor, but are replaced with airfoil bearings, and the rigidity and durability are relatively weak, and friction is reduced at the initial stage of operation. It further includes an air supply unit 500 that is a configuration that can solve the problem of airfoil bearings whose performance is rapidly deteriorated. Hereinafter, the basic configuration and operation of the air compressor 100 of the present invention will be described in general with reference to FIG. 3 and the like.

As exemplarily shown in FIG. 3 , the air compressor 100 of the present invention basically includes an impeller 110 , an impeller chamber 120 , and a front bearing 151 . Each part will be described in more detail as follows.

The impeller 110 includes a core 111 and a plurality of blades 112 , and rotates by a rotating shaft 131 to suck in, compress, and discharge gas. The blades 112 are radially connected around the core 111 , and the rotation shaft 131 may be inserted into and connected to the core 111 of the impeller 110 as shown. According to the shape of the blade 112, as the impeller 110 rotates, the gas in front of the core 111 flows along the blade 112 and proceeds to the end of the blade 112, in this process, centrifugal force As the flow rate of the gas increases, compression of the gas can occur.

The impeller chamber 120 is a type of case for accommodating and supporting the impeller 110, and as shown, an impeller chamber front member including a gas intake port 121a, a gas discharge port 121b, and a gas flow path 121c. (121) and comprising an impeller chamber rear member (122). 4 is a schematic diagram of the air flow in the air compressor of the present invention (reference numerals except for the bearings 151, 152, and 153 in FIG. 4 are omitted for convenience), indicated by the arrows in FIG. As shown, as the impeller 110 rotates, gas is sucked in through the gas inlet 121a formed on the same axis as the core 111 , and the sucked gas moves along the blade 112 . It is compressed while flowing into the flow path 121c, and the compressed gas is collected at the gas outlet 121b and discharged to the outside. The air flow by the air supply unit 500 will be described in more detail later as a first embodiment and a second embodiment.

The front bearing 151 serves to support the front end side of the rotating shaft 131, and is supported by the impeller chamber rear member 122. In the present invention, the front bearing 151 is an airfoil journal bearing. is formed The rear end of the rotation shaft 131 is also provided with a rear bearing 152 as shown in FIG. 3 to support the rotation shaft 131 (how the rear bearing 152 is supported, etc. will be described later in more detail.) explain).

A motor is generally used as a power source for rotating the rotating shaft of the air compressor 100 . 3 and the like show a motor type of an air compressor that is currently widely used. In brief, the rotating shaft 131 itself is provided with various electronic components for generating rotational force. However, the present invention is not limited thereto, for example, a motor having a separate shaft is provided, and various modifications such as the rotation shaft 131 of the air compressor 100 may be coupled to the shaft of the motor. is of course possible. Hereinafter, a motor-related configuration of the air compressor 100 will be briefly described based on the embodiment shown in FIG. 3 and the like. In this case, the air compressor 100 further includes a motor 130 and a motor chamber 140 .

The motor 130 is connected to the rear end of the impeller 110 through the rotation shaft 131 to rotate the impeller 110 . To describe the configuration of the motor 130 in more detail, the motor 130 includes a rotor 132 coupled to an outer circumferential surface of the rotation shaft 131 and a plate disposed at a position corresponding to the rotor 132 . The stator 133 is composed of a 133a and a coil 133b and is fixedly supported on the inner circumferential surface of the motor chamber 140 . A magnetic field change occurs between the rotor 132 and the stator 133 according to a power signal applied to the stator 133 , and a rotational force is generated by this magnetic field change so that the rotating shaft 131 can rotate. .

The motor chamber 140 is connected to the rear end of the impeller chamber 120 and serves to accommodate and support the motor 130 . As shown in FIG. 3 , the motor room 140 includes a motor room front member 141 and a motor room rear member 142 , and the motor room front member 141 and the motor room rear member ( The motor 130 is provided in the space formed between the couplings 142 . Meanwhile, a substrate for controlling the motor 130 may be further provided in the motor room 140 , which may be provided at the rear of the motor room rear member 142 . In order to protect the substrate, the motor room may be further provided. A cover 143 may be further provided. The motor room front member 141 may be provided with a main water jacket 141a that is formed in the form of a cavity in the motor room front member 141 and accommodates cooling water therein, and also the rear of the motor room. The member 142 may further include a sub-water jacket 142a formed in the form of a cavity in the motor compartment rear member 142 and accommodating cooling water therein, whereby the motor 130 is The heat generated in the can be cooled.

At this time, at the rear of the rotary shaft 131 , the rear bearing 152 is supported by the motor room rear member 142 or the turbine room member to support the rear end side of the rotary shaft 131 , and is formed in the form of an airfoil journal bearing. ) may be provided.

In addition, a flange 131a is protruded from the rear end of the rotating shaft 131 to support the rear end of the rotating shaft 131 (as shown in the embodiment of FIG. 3 , the rear member of the motor compartment 142, other types of When a rotational drive source is provided, it may be inserted into a groove formed in a member provided to support the rotational drive source). The flange 131a may serve to guide the rotation shaft 131 not to deviate from its original position. In this case, an end bearing formed in the form of an airfoil thrust bearing between the flange 131a and the groove. This may be provided.

In the present invention, all bearings provided in the air compressor 100, such as the front bearing 151, the rear bearing 152, and the end bearing 153, are made in the form of an airfoil bearing as described above, and the operation By initially injecting air into the airfoil bearing by the air supply unit 500, sufficient dynamic pressure is not generated at the beginning of the operation of the air compressor, so that an air gap between the foil-rotation shaft is not sufficiently formed, and contact between the foil-rotation shaft occurs. solve the problem fundamentally. Hereinafter, a detailed configuration of the air supply unit 500 will be described.

Configuration of the air storage unit provided in the air compressor of the present invention

The air supply unit 500 provided in the air compressor 100 of the present invention, the air supply unit 500, an air storage unit 510 for storing compressed air, and air to the air storage unit 510 It may include a storage flow path 520 for supplying and storing, a supply flow path 530 for discharging air from the air storage unit 510 , and a control unit 550 for controlling opening and closing thereof.

The air storage unit 510 is formed in a tank shape and serves to store compressed air. The air storage unit 510 may be integrally configured with the air compressor 100 as shown in FIG. 3, or may be configured separately from the air compressor 100 as shown in FIG. 7 if necessary. may be

The storage passage 520 is configured such that one end is connected to the air storage unit 510 and the other end is connected to the gas outlet 121b. Accordingly, a portion of the compressed air discharged through the gas discharge port 121b may be supplied and stored in the air storage unit 510 .

The supply passage 530 is configured such that one end is connected to the air storage unit 510 and the other end is connected to the front bearing 151 . Accordingly, the compressed air discharged from the air storage unit 510 can be supplied to the inside of the front bearing 151 . Meanwhile, as described above, in addition to the front bearing 151 , the air compressor 100 may include various other bearings such as the rear bearing 152 or the end bearing 153 , and these bearings also have the supply flow path. It is natural that flow paths such as 530 may be connected to each other. Specifically, in the air compressor 100 , similarly to the supply flow path 530 connecting the air storage unit 510 - the front bearing 151 , the air storage unit 510 - the rear bearing ( An additional supply passage 530a connecting the 152 , or an additional supply passage 530b connecting the air storage unit 510 and the end bearing 153 may be further provided.

The control unit 550 serves to control opening and closing of the storage passage 520 or the supply passage 530 . As described above, the air compressor 100 of the present invention supplies air to the inside of the bearings 151 , 152 , 153 formed in the form of an airfoil bearing at the initial stage of operation. In the related art, the rotation shaft 131 is in a state in which an air gap is not properly formed (that is, the rotation shaft 131 and the bearings 151, 152, and 153 are in contact) because sufficient dynamic pressure has not yet been generated at the initial stage of operation. ), the friction reduction performance is lowered and the risk of bearing damage is greatly increased. However, according to the present invention, a sufficient air gap is formed in advance by supplying air to the inside of the bearings 151, 152, and 153 at the initial stage of operation as described above. Accordingly, even if the rotation shaft 131 does not reach a rotational speed sufficient to generate dynamic pressure for forming an appropriate air gap (that is, at the beginning of operation), the bearings 151, 152, and 153 It makes it possible to obtain the effect of improving friction reduction performance and reducing the risk of bearing damage by preventing unnecessary contact with the bearing. A detailed step of controlling the air supply to the bearing by the controller 550 will be described in more detail later.

5 shows one embodiment of a bearing air supply structure. As described above, the supply passages 530 , 530a and 530b are configured to supply air to the inside of the bearings 151 , 152 , 153 provided in the air compressor 100 . At this time, in order to uniformly and well supply air to the entire interior of the bearings 151, 152, and 153, the other ends of the supply passages 530, 530a, 530b are as shown in FIG. It is preferable that the bearings 151, 152, and 153 are formed so as to be branched into a plurality and connected to the inside of the bearings 151, 152, and 153. Although the supply flow path 530-the front bearing 151 is illustrated as an embodiment in FIG. 5, the additional supply flow path 530a-the rear bearing 152 or the additional supply flow path 530b-the end It goes without saying that the connection of the bearing 153 may also be made as shown in FIG. 5 .

FIG. 6 shows the front bearing 151 supported by the impeller chamber rear member 122 as an example of an airfoil journal bearing according to a bearing air supply structure. At this time, the supply passage 530 is formed in the form of a passage formed by drilling the rear member 122 of the impeller chamber. The front bearing 151 is in the form of an airfoil journal bearing and includes a housing 151a, a bump foil 151b, and a top foil 151c. At this time, a communication path 151d is formed in the housing 151a to communicate the supply path 530 and the inside of the front bearing 151 . As such, the compressed air supplied through the supply passage 530 enters the inside of the front bearing 151 through the communication passage 151d. can get clogged In order to solve this problem, as shown in FIG. 6 , a communication hole 151e may be formed in the top foil 151c at a position close to the communication path 151d. Accordingly, air may sequentially pass through the supply passage 530 - the communication passage 151d - and the communication hole 151e to be smoothly supplied into the front bearing 151 . Again, although the front bearing 151 is illustrated in FIG. 6 as an embodiment, the rear bearing 152 or the end bearing 153 may also be configured as in FIG. 6 , of course.

First embodiment of the air compressor of the present invention

3 shows a first embodiment of the air compressor of the present invention. In the air compressor 100 according to the first embodiment, valves 525, 535, 535a, and 535b are provided for each of the flow passages 520, 530, 530a, and 530b, respectively. . More specifically, the air supply unit 500 according to the first embodiment is provided on the storage flow path valve 525 provided on the storage flow path 520 , the supply flow path 530 , and the control unit 550 . ) further includes a supply channel valve 535 whose opening and closing is controlled. Of course, as more bearings are provided, more valves may be provided in the supply passages that are further provided. It may further include a supply passage valve (535a) and an additional supply passage valve (535b) provided on the additional supply passage (530b).

At this time, the opening and closing of the supply flow valves 535 , 535a , and 535b provided in the supply flow passages 530 , 530a and 530b are controlled by the controller 550 . Meanwhile, the storage passage valve 525 provided in the storage passage 520 may also be controlled to be opened and closed by the controller 550, or may be opened and closed automatically by a differential pressure.

As described above, the air compressor 100 of the present invention supplies air to the inside of the bearings 151 , 152 , 153 using the air supply unit 500 at the initial stage of operation to provide the rotation shaft 131 . - The main role is to form an air gap between the bearings 151, 152, and 153 in advance. That is, the supply passage valves 535, 535a, and 535b provided in the supply passages 530, 530a, and 530b for supplying air to the bearings 151, 152, and 153 are, Since the operation of the air compressor 100 must be started (that is, the closed one must be opened) before starting, it cannot be operated according to the operation of the air compressor 100, and therefore opening and closing by the separate control unit 550 is performed. have to be controlled.

However, in the case of the storage passage valve 525 , the air storage unit 510 is already filled with compressed air to some extent and is refilled by the amount that has escaped through the supply passages 530 , 530a and 530b . There is no need to always operate, and of course, there is no need to operate before the air compressor 100 starts. Therefore, the storage flow valve 525 may, of course, be controlled to be opened and closed by the control unit 550 , but may be operated according to the operating state of the air compressor 100 . Specifically, it is as follows.

The storage flow valve 525 may be formed in the form of a check valve that is opened when the pressure in the gas outlet 121b is greater than the pressure in the air storage 510 and closed otherwise. In this case, as well as the normal pressure in the air storage unit 510, it is obvious that the pressure formed in the gas outlet 121b during normal operation of the air compressor 100 should be greater than that of the air compressor 100. When the operation of the air supply unit 500 is started and the air escapes from the air storage unit 510 through the supply passages 530, 530a and 530b, the pressure in the air storage unit 510 is gradually lowered. , as this process progresses, a time comes when the pressure in the gas outlet 121b becomes greater than the pressure in the air storage unit 510 . At this point, as the storage passage valve 525 is opened, the compressed air compressed by the impeller 110 is supplied to the air supply unit 500 through the storage passage 520 . As the air is supplied and the loss is gradually filled in this way, the pressure in the air supply unit 500 also gradually increases again, and as this process progresses, the pressure in the air storage unit 510 again becomes higher than the pressure in the gas outlet 121b. becomes large, and the storage passage valve 525 is closed.

Second embodiment of the air compressor of the present invention

7 shows a second embodiment of the air compressor of the present invention. In the first embodiment, valves 525, 535, 535a, and 535b are provided for each of the flow paths 520, 530, 530a, and 530b formed in the air compressor 100, respectively. However, in the second embodiment, the flow paths 520 , 530 , 530a , 530b are integrated with each other and connected to the air storage unit 510 , and accordingly, only a single valve is provided. More specifically, the air supply unit 500 according to the second embodiment integrates the storage flow path 520 and the supply flow path 530 to connect the air storage unit 510 to the integrated flow path 540 . further includes Of course, as more bearings are provided, additional supply passages may be further integrated into the integrated passage 540 . In this case, the air supply unit 500 according to the first embodiment includes the storage passage 520 and The supply passage 530 , the additional supply passage 530a , and the additional supply passage 530b may all be integrated and connected to the air storage unit 510 .

At this time, as shown in FIG. 7 , opening and closing is controlled by the control unit 550 at a portion where the integrated flow path 540 and the other flow paths 520 , 530 , 530a and 530b are connected to each other. An integrated flow valve 545 formed in the form of a three-way valve may be provided. Specifically, since the integrated flow valve 545 is in the form of a three-way valve, there is a 1/2/3 flow port. When the storage passage 520 is provided in the second distribution port, and the supply passage 530 (the additional supply passage 530a, the additional supply passage 530b is further provided in the third distribution port, the supply passage 530) , the additional supply passage 530a and the additional supply passage 530b) are connected. Similarly in the case of the integrated flow valve 545, the supply flow paths 530, 530a and 530b are opened at the beginning of operation to supply air to the bearings 151, 152, and 153, and the When the air in the air storage unit 510 is lost and the pressure drops, the storage flow path 520 is opened to store the air.

Air compressor control method of the present invention

Although the foregoing description has been focused on the device configuration of the air compressor 100 of the present invention, the following will be described in more detail in terms of a method of controlling the air compressor 100 of the present invention. The air compressor 100 control method of the present invention, in brief, uses the impeller 110 rotated by the rotating shaft 131 to suck in and compress the gas and discharge it, and a journal bearing or around the rotating shaft 131 . At least one airfoil bearing formed in the form of a thrust bearing is provided, and an air supply unit 500 that receives and stores a portion of the compressed air discharged from the air compressor 100 and supplies air to the inside of the airfoil bearing. It is a method of controlling the air compressor 100 comprising a. This method of controlling the air compressor 100 of the present invention, as shown in the flowchart of FIG. 8, includes a starting standby step, an air supply step, a starting step, an air storage step, and a supply stop step.

The starting standby step is a step in which the rotating shaft 131 is in a stopped state, that is, a state before the start of the air compressor 100 is started. In the starting standby step, the rotating shaft 131 is brought down by gravity to be in contact with the airfoil bearing. In the conventional case, when the air compressor 100 is started in this state, a frictional force is severely generated in the process of starting the rotation while the rotating shaft 131 is in contact with the airfoil bearing, and the airfoil bearing is damaged. I had a problem wearing it.

In the air supply step, air is supplied to the inside of the airfoil bearing by the air supply unit 500 . As described above, the compressed air stored in the air storage unit 510 is supplied into the bearings 151, 152 and 153 through the supply passages 530, 530a and 530b. As the rotation shaft 131 is lifted up by the pressure of the supplied air (even though it is not rotating yet), an air gap is formed between the rotation shaft 131 and the airfoil bearing.

At this time, in the air supply step, whether air is supplied is controlled by the automatic control valve whose opening and closing is controlled by the control unit 550 . As described above, since the air supply operation must be made in advance before the air compressor 100 operation starts, it should not be made in such a way that a valve is opened in connection with the operation of the air compressor 100, and the air compressor Even if 100 is stopped, an air supply operation must be performed by the separate control unit 550 so that the valve can be opened.

As such, when an air gap is formed between the rotary shaft 131 and the airfoil bearing by the air supply step, the starting step of starting the air compressor 100 by rotating the rotary shaft 131 is performed. As described above, in the present invention, since the rotating shaft 131 rotates in a state in which the air gap is formed, the air compressor 100 is started in a state in which the friction or damage problem that occurred in the conventional case is fundamentally resolved. be able to

On the other hand, when the air stored in the air storage unit 510 is reduced by supplying air to the airfoil bearing by the air supply step, the amount of air must be refilled. Accordingly, the air storage step is performed, and a part of the compressed air sucked and compressed by the start of the air compressor 100 and discharged is stored in the air supply unit 500 .

At this time, in the air storage step, similarly to the air supply step, whether or not air is stored may be controlled by an automatic control valve whose opening/closing is controlled by the controller 550 . At this time, the air storage control of the controller 550 may be configured to start storing air when, for example, the rotational speed of the rotating shaft 131 reaches a predetermined standard, or the rotation of the rotating shaft 131 is started. After a predetermined time has elapsed, the air storage may be started. On the other hand, unlike the air supply operation that must be performed in advance before the operation of the air compressor 100 starts, the air storage operation is performed after the air is sufficiently exhausted, that is, after the air compressor 100 operates sufficiently. will be done in Therefore, opening and closing can be made in connection with the operation of the air compressor 100. In this case, specifically, in the air storage step, the pressure in the space from which the gas is discharged from the air compressor 100 is the air supply unit 500. If the pressure in the air storage space is greater than the pressure of the air storage space of the open or otherwise closed by the check valve can be made to control whether or not to store the air.

On the other hand, when the rotation shaft 131 rotates at a high speed of a normal operation level after the initial operation, dynamic pressure is generated around the rotation shaft 131 by the rotation of the rotation shaft 131, and thus there is no separate air supply. Naturally, an air gap is formed between the rotation shaft 131 and the airfoil bearing. Therefore, at this point, it becomes unnecessary to continuously supply air to the airfoil bearing. Therefore, when the rotating shaft 131 rotates at a high speed of a normal operating level, the supply stopping step of stopping the supply of air into the airfoil bearing by the air supply unit 500 is performed, and unnecessary waste of air is prevented. block At this time, the supply stop control of the control unit 550 may be made to stop the air supply when the rotational speed of the rotating shaft 131 reaches a predetermined criterion, or after the rotation of the rotating shaft 131 starts, a predetermined It may also be made to stop air storage over time.

Additionally, although it is illustrated in FIG. 8 that the air storage step precedes the supply interruption step for convenience, the air storage step and the supply stop step are not highly related to each other, so either step may be performed first.

As such, the air supply unit 500 actively operates at the initial stage of operation of the air compressor 100 to form an air gap between the rotation shaft 131 and the airfoil bearing in advance, thereby preventing friction and damage problems. do However, when the air compressor 100 returns to normal operation after the initial stage of operation, the air supply unit 500 does not need to operate any more, and since the supply interruption step is performed, the operation of the air supply unit 500 is substantially Most of it is completed (the air storage step may be further performed after the supply stop step). Thereafter, the air compressor 100 itself may stop the operation after sufficiently performing the operation according to the user's need, and this step is referred to as a start-up termination step. As such, when the operation of the air compressor 100 is terminated, the rotational shaft 131 returns to the starting standby step of waiting in a stopped state until the air compressor 100 is started again.

The present invention is not limited to the above-described embodiments, and the scope of application is varied, and anyone with ordinary knowledge in the field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims It goes without saying that various modifications are possible.

100: air compressor
110: impeller
111: core 112: blade
120: impeller chamber
121: impeller chamber front member 121a: gas inlet
121b: gas discharge port 121c: gas flow path
122: impeller chamber rear member
130: motor 131: rotation shaft
132: rotor 133: stator
133a: plate 133b: coil
140: motor room
141: motor room front member 141a: main water jacket
142: motor compartment rear member 142a: sub water jacket
143: motor chamber cover member
151: front bearing 152: rear bearing
153: end bearing
500: air supply 510: air storage
520: storage passage 525: storage passage valve
530: supply passage 535: supply passage valve
530a: additional supply passage 535a: additional supply passage valve
530b: additional supply passage 535b: additional supply passage valve
540: integrated flow path 545: integrated flow path valve
550: control unit

Claims (18)

At least one airfoil bearing formed in the form of a journal bearing or a thrust bearing is provided around the rotating shaft 131 to suck and compress gas using the impeller 110 rotated by the rotating shaft 131 and discharge it. In the air compressor (100),
the impeller 110 including a core 111 and a plurality of blades 112 and rotating by the rotation shaft 131 to suck and compress gas and discharge it;
It includes an impeller chamber front member 121 and an impeller chamber rear member 122 including a gas inlet 121a, a gas outlet 121b, and a gas flow path 121c, and receiving and supporting the impeller 110 impeller chamber 120;
a front bearing 151 supported by the impeller chamber rear member 122 to support the front end side of the rotation shaft 131 and formed in the form of an airfoil journal bearing;
an air supply unit 500 that receives and stores a portion of the compressed air discharged from the air compressor 100 and supplies air to the inside of the airfoil bearing including the front bearing 151;
including,
The air supply unit 500,
An air storage unit 510 for storing compressed air, one end connected to the air storage unit 510 and the other end of the gas discharge port 121b and the other end to receive and store a portion of the compressed air discharged through the gas discharge port 121b A storage flow path 520 connected, one end connected to the air storage unit 510 and a supply flow path 530 having the other end connected to the front bearing 151 to supply air to the inside of the front bearing 151, Controlling the opening and closing of an integrated flow path 540 , the storage flow path 520 or the supply flow path 530 that integrates the storage flow path 520 and the supply flow path 530 and connects to the air storage unit 510 . Air compressor (100), characterized in that it comprises a control unit (550).
delete According to claim 1, wherein the air compressor (100),
As the impeller 110 rotates, gas is sucked in through the gas inlet 121a formed coaxially with the core 111, and the sucked gas flows along the blade 112 to the gas flow path ( 121c) and compressed while flowing, the compressed gas is collected at the gas outlet (121b) and discharged to the outside.
According to claim 1, wherein the air supply unit 500,
The storage flow path valve 525 provided on the storage flow path 520, the supply flow path valve 535 provided on the supply flow path 530, the opening and closing is controlled by the control unit (550) characterized in that it further comprises The air compressor (100).
According to claim 4, The air supply unit 500,
The storage flow valve 525 is formed in the form of a check valve that opens when the pressure in the gas outlet 121b is greater than the pressure in the air storage 510 and closes otherwise,
The air compressor (100), characterized in that the storage flow valve (525) is formed to be opened and closed by the control unit (550).
delete According to claim 1, wherein the air supply unit 500,
The air compressor (100), which is provided on the integrated flow path (540) and further comprises an integrated flow path valve (545) formed in the form of a three-way valve whose opening and closing is controlled by the control unit (550).
According to claim 1, wherein the air compressor (100),
a motor 130 connected to the rear end of the impeller 110 through the rotation shaft 131 to rotate the impeller 110; a motor room including a front member of the motor room 141 and a rear member of the motor room 142, connected to the rear end of the impeller room 120, and receiving and supporting the motor 130; further comprising,
a rear bearing 152 supported by the motor chamber rear member 142 or the turbine chamber member to support the rear end side of the rotation shaft 131 and formed in the form of an airfoil journal bearing;
Air compressor 100, characterized in that it further comprises.
According to claim 8, The air supply unit 500,
One end is connected to the air storage unit (510) and the other end is characterized in that it further comprises an additional supply passage (530a) connected to the rear bearing (152) to supply air to the inside of the rear bearing (152). Air compressor (100).
The method of claim 9, wherein the air supply unit 500,
The air compressor (100), which is provided on the additional supply passage (530a) and further includes an additional supply passage valve (535a) that is opened and closed by the control unit (550).
According to claim 8, The air compressor (100),
a flange (131a) protruding from the rear end of the rotation shaft (131) and inserted into a groove formed in the motor chamber rear member (142) or the turbine chamber member;
an end bearing 153 provided between the flange 131a and the groove and formed in the form of an airfoil thrust bearing;
Air compressor 100, characterized in that it further comprises.
The method of claim 11, wherein the air supply unit 500,
One end is connected to the air storage unit (510) and the other end further comprises an additional supply passage (530b) connected to the end bearing (153) to supply air to the inside of the end bearing (153) Air compressor (100).
According to claim 12, The air supply unit 500,
The air compressor (100), which is provided on the additional supply passage (530b) and further includes an additional supply passage valve (535b) whose opening and closing is controlled by the control unit (550).
In the air compressor (100) control method for controlling the air compressor (100) according to claim 1,
a starting standby step of waiting in a state in which the rotating shaft 131 is stopped;
an air supply step in which air is supplied through the integrated passage 540 and the supply passage 530 to the inside of the airfoil bearing by the air supply unit 500;
a starting step of starting the air compressor 100 by rotating the rotary shaft 131 when an air gap is formed between the rotary shaft 131 and the airfoil bearing by the air supply step;
an air storage step in which a part of compressed air suctioned and compressed by the operation of the air compressor 100 and discharged is stored in the air supply unit 500 through the storage passage 520 and the integrated passage 540;
a supply stopping step in which the air supply to the inside of the airfoil bearing is stopped by the air supply unit 500;
Air compressor 100 control method comprising a.
15. The method of claim 14, wherein the air compressor 100 control method,
In the air storage step, if the pressure in the space from which the gas is discharged from the air compressor 100 is greater than the pressure in the air storage space of the air supply unit 500, the air is stored by the check valve, which is opened or closed otherwise. controlled or
In the air storage step, the control method of the air compressor (100), characterized in that the storage of air is controlled by an automatic control valve that is opened and closed by the control unit (550).
The method of claim 15, wherein the air compressor (100) control method comprises:
In the air storage step, by the control unit 550,
Air compressor ( 100) Control method.
15. The method of claim 14, wherein the air compressor 100 control method,
In the air supply step, the control method of the air compressor (100), characterized in that the supply of air is controlled by an automatic control valve whose opening and closing is controlled by the controller (550).
15. The method of claim 14, wherein the air compressor 100 control method,
In the supply interruption step, by the control unit 550,
Air compressor ( 100) Control method.

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